Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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FXUS64 KLIX 250901
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
401 AM CDT Mon Mar 25 2024

...New SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(Today through Tuesday)
Issued at 345 AM CDT Mon Mar 25 2024

Upper trough off the Atlantic Coast and from the Northern Plains
to Arizona. At the surface, high pressure extended along the
length of the Atlantic Coast. Deepening low pressure was over
western Kansas. Southeasterly winds were pumping moisture into the
area early this morning. At 3 AM CDT under mostly cloudy skies,
temperatures were in the upper 50s across southwest Mississippi
and in the mid to upper 60s elsewhere.

Multiple potential hazards in the first 24 hours of the forecast
before the weather quiets down for a while.

Surface low over western Kansas this morning will move northeast
to Lake Superior by Tuesday evening as the southern Rockies
impulse gets pulled northeastward by an upper low over the
Canadian Prairie Provinces. The strong pressure gradient between
the East Coast high and the low over Kansas will continue to pump
moisture northward into the area on the strength of a 50+ knot
low level jet. Dew points that are currently near 60 will increase
to the mid and upper 60s this afternoon. Precipitable water
values that were near an inch at this writing will be much closer
to 1.5 inches by late this afternoon. While the best jet dynamics
will be to the north of the CWA in Mississippi and points north,
we`ll still have more than sufficient low level shear in place.
SBCAPE is forecast to increase to around 1000 J/kg just ahead of
the front and SRH values near or exceeding 400 m2/s2 should aid in
the development of a QLCS to our west late this afternoon,
although there could be isolated supercells in advance of that
line. The main threat will be damaging wind gusts, but QLCS
tornadoes will also be possible considering the strong
shear/helicity values. If we do get supercells in advance of the
line, there will be the potential for longer track tornadoes.
The main line is expected to move across the local area during
the evening and overnight hours, with most or all of the
thunderstorms moving into Alabama by sunrise Tuesday.

Heavy rainfall will also be a threat, especially in areas that see
supercells develop in advance of the line. Areal average rainfall
amounts are expected to be around 1.5 inches, but spot higher
amounts are likely, especially across southwest Mississippi.

The other significant concern will be strong gradient winds.
Already starting to see wind gusts in the 20 to 30 mph range over
portions of southeast Louisiana, and those will get stronger
during the day. Sustained winds as high as 25 mph, with occasional
gusts near or above 40 mph should become common by midday, and
plan no changes to the Wind Advisory. Additionally, the onshore
winds will raise water levels on southeast and south facing
shorelines today, potentially causing minor coastal flooding in
some areas. At this time, not anticipating changes to the Coastal
Flood Advisory, either, as the event looks to be primarily during
the evening high tide cycle, with a wind shift tomorrow morning
easing concerns. Dry air moving into the area during the day
tomorrow should clear out most of the clouds by midday.

Temperature forecast will be a bit tricky in the short term.
Clouds today are likely to hold highs in the mid 70s, but if any
significant breaks in the clouds develop, temperatures near 80 or
higher become more likely. This would also lead to destabilizing
the airmass and potentially more, stronger storms. Overnight lows
will be dependent on timing of the passage of the trough/front.
Highs Tuesday afternoon should actually be higher than today, if
we get sunshine.

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 345 AM CDT Mon Mar 25 2024

Weather pattern becomes much quieter beyond tomorrow. At the
surface, high pressure will be moving into the area tomorrow night
and Wednesday, but we`ll still be under the upper trough until
sometime Thursday. That`s likely to produce a good bit of mid and
high cloud cover Wednesday into Thursday morning, but no
significant precipitation. Beyond that point, upper ridging
spreads across the middle of the country for the Easter weekend.

Temperatures will be on the coolish side for overnight lows from
Wednesday morning until about Saturday morning with overnight lows
generally in the 40s for much of the area away from the immediate
south shore of Lake Pontchartrain. Daytime highs for Wednesday
through Friday should generally be in the 70s. As we get into the
weekend and start tapping into southerly winds again, temperatures
will warm into the lower and mid 80s for Sunday and Monday. Can`t
rule out a few upper 80s on Monday considering that MOS guidance
does skew toward climatology a bit on Day 8, and both ECMWF and
GFS numbers for those days are +10F from normal. Limiting
consideration is that the ECMWF operational numbers for Monday are
pretty much the high member (outlier) of the ensemble. The ECMWF
and GFS numbers are remarkably similar for most of the period,
leaving not much of a target of opportunity by departing from the
NBM values.

&&

.AVIATION...
(06Z TAFS)
Issued at 1218 AM CDT Mon Mar 25 2024

Most terminals are currently in VFR status but this will change
overnight. Low cigs will continue to develop this morning and
should see MVFR cigs over all sites between 10-14z. Winds will
also ramp up through the morning and day hours with gusts around
35 to 40 kts out of the south-southeast. LLWS could be a problem
for some sites but with decent mixing expected through the day
winds will just be strong from the sfc up to 2-3-4k ft. Convection
likely won`t begin to impact the far northwestern terminals till
after 20/21z and then slowly works east across the area through
the evening and into the overnight hours. /CAB/

&&

.MARINE...
Issued at 345 AM CDT Mon Mar 25 2024

Already seeing 25-30 knot sustained winds over the outer open
waters at 3 AM CDT, and those winds should continue to spread
toward the coast and inland, so see no need to make adjustments to
the Small Craft Advisory/Gale Warning. Hazardous conditions should
relax somewhat for Tuesday into Wednesday, but Small Craft
Exercise Caution headlines or Small Craft Advisories look to be
necessary later Wednesday into Thursday due to the cool, dry air
moving over the waters. Conditions should then improve for a
longer period into the Easter weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  77  58  77  45 /  60  90  10   0
BTR  81  61  80  50 /  70  90   0   0
ASD  78  62  81  51 /  40  90  20   0
MSY  80  64  80  57 /  40  90  20   0
GPT  75  62  79  52 /  30  90  50  10
PQL  76  63  80  52 /  30  80  60  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Wind Advisory from 7 AM this morning to 4 AM CDT Tuesday for
     LAZ034>037-039-046>048-056>060-064>071-076>090.

     Coastal Flood Advisory from 7 AM this morning to 4 AM CDT
     Tuesday for LAZ069-070-076-078.

GM...Small Craft Advisory until 7 AM CDT this morning for GMZ530-532-
     534-536-538-550-552-555-557-570-572-575-577.

     Gale Warning from 7 AM this morning to 4 AM CDT Tuesday for
     GMZ530-532-534-536-538-550-552-555-557-570-572-575-577.

MS...Wind Advisory from 7 AM this morning to 4 AM CDT Tuesday for
     MSZ068>071-077-083>088.

     Coastal Flood Advisory from 7 AM this morning to 4 AM CDT
     Tuesday for MSZ086.

GM...Small Craft Advisory until 7 AM CDT this morning for GMZ532-534-
     536-538-550-552-555-557-570-572-575-577.

     Gale Warning from 7 AM this morning to 4 AM CDT Tuesday for
     GMZ532-534-536-538-550-552-555-557-570-572-575-577.

&&

$$

SHORT TERM...RW
LONG TERM....RW
AVIATION...CAB
MARINE...RW


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